Whipple 3.875, or 3.750 Pulley? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

ccutaia · 09-29-2020, 02:21 PM

Help me decide, I am upgrading my 2012 SS and have everything nailed down accept pulley size for the SC. The car has: Whipple 2.9, 1 7/8 long tube headers w/high flow CAT's, 3" FlowMaster exhaust, ZL1 fuel pump, 85LB injectors, CAI ram air cold air intake. Last but not least, WHAT SIZE PULLEY 3.875, or 3.75 pro's and con's? I want to keep the car as reliable as possible.

Greenhornet2 · 10-02-2020, 12:14 PM

3.875 with stock cam. 3.75 if cammed. I have a 3.875 used for a couple thousand miles i can send you you $100

ccutaia · 10-02-2020, 12:56 PM

Thanks for the info! As far as the pulley I have the order placed with the speed shop just making sure I did the right move. Do you know any con's to running a 3.75 pulley with a stock lower end?

Quote:

Originally Posted by Greenhornet2

3.875 with stock cam. 3.75 if cammed. I have a 3.875 used for a couple thousand miles i can send you you $100

Greenhornet2 · 10-05-2020, 10:26 AM

Quote:

Originally Posted by ccutaia

Thanks for the info! As far as the pulley I have the order placed with the speed shop just making sure I did the right move. Do you know any con's to running a 3.75 pulley with a stock lower end?

The cons are with a stock cam you will be pushing the boost up past 12psi. The tune will need to be more conservative to keep you out of knock retard. The engine is more likely to get some knock on the stock cam so adding more boost compounds the problem. As far as the bottom end that it more about the amount of power you are putting out and being sure to keep out of detonation. With a good tune these are pretty safe up to 800whp but anything could happen, more safe at 600whp. I would be thinking about a cam, they really help these engine breathe which makes the car much happier under boost.

Juiced1 · 10-16-2020, 08:56 AM

10 psi is really as far as you want to go on a stock bottom end. After that it can get dicey. Every .125" of pulley is usually another pound of boost with the Whipple kit. Adding long tubes will usually drop a psi, adding a cam will usually drop a psi. Good choice on the Whipple. They really are a blast.

09-29-2020, 02:21 PM	#1
ccutaia Drives: 2012 Black 2SS, Join Date: Nov 2011 Location: Knoxville TN Posts: 145 View My Garage	Whipple 3.875, or 3.750 Pulley? Help me decide, I am upgrading my 2012 SS and have everything nailed down accept pulley size for the SC. The car has: Whipple 2.9, 1 7/8 long tube headers w/high flow CAT's, 3" FlowMaster exhaust, ZL1 fuel pump, 85LB injectors, CAI ram air cold air intake. Last but not least, WHAT SIZE PULLEY 3.875, or 3.75 pro's and con's? I want to keep the car as reliable as possible. __________________ Last edited by ccutaia; 09-30-2020 at 10:58 AM.

10-02-2020, 12:14 PM	#2
Greenhornet2 Drives: 2011 Camaro 2SS LS3 Whipple Join Date: May 2019 Location: Connecticut Posts: 1,925	3.875 with stock cam. 3.75 if cammed. I have a 3.875 used for a couple thousand miles i can send you you $100 __________________ Whipple 2.9 CAI ID1050x injectors ZL1 Pump JRE FPCM JMS Voltage booster JRE Rough Idle blower cam BTR .660 springs CHE trunnion kit 1 7/8 Speed Engineering Borla Atak JRE scoop 1.5" lowering springs BMR trailing arms and toe links Cradle inserts 704WHP 603WTQ 93 octane

10-16-2020, 08:56 AM	#5
Juiced1 Account Suspended Drives: 2012 2SS CAMARO 45th Join Date: Apr 2011 Location: St. Charles, IL Posts: 18,663	10 psi is really as far as you want to go on a stock bottom end. After that it can get dicey. Every .125" of pulley is usually another pound of boost with the Whipple kit. Adding long tubes will usually drop a psi, adding a cam will usually drop a psi. Good choice on the Whipple. They really are a blast.